x = int(input())

if x < 30:
    print("No")
elif x >= 30:
    print("Yes") x = int(input()) x int(input()) int input() input if x < 30:
    print("No")
elif x >= 30:
    print("Yes") x < 30 x 30 print("No") print "No" elif x >= 30:
    print("Yes") x >= 30 x 30 print("Yes") print "Yes" x = int(input()) int(input()) x
x = int(input())

if x < 30:
    print("No")
elif x >= 30:
    print("Yes")